The following U.S. patent applications are hereby fully incorporated by reference:
Application Ser. No. 09/298,671, filed Apr. 23, 1999, entitled xe2x80x9cFEATURES OF MAIN CONTROL COMPUTER FOR A POWER MACHINExe2x80x9d; and
Application Ser. No. 29/103,252, filed Apr. 12, 1999, entitled xe2x80x9cDISPLAY PANEL FOR POWER MACHINExe2x80x9d;
Application Ser. No. 29/103,267, filed Apr. 12, 1999, entitled xe2x80x9cDISPLAY PANEL FOR POWER MACHINExe2x80x9d;
Application Ser. No. 29/103,256, filed Apr. 12, 1999, entitled xe2x80x9cDISPLAY PANEL FOR POWER MACHINExe2x80x9d; and
Application Ser. No. 09/326,108, filed Jun. 4, 1999, entitled xe2x80x9cUSER INTERFACE FUNCTIONALITY FOR POWER MACHINE CONTROL SYSTEM, all of which are assigned to the same assignee as the present invention.
The present invention generally relates to power machines. More specifically, the present invention relates to a diagnostic unit (or service tool) for use with a power machine.
Power machines, such as skid steer loaders, typically have a frame which supports a cab and a movable lift arm which, in turn, supports a work tool such as a bucket. The movable lift arm is pivotally coupled to the frame of the skid steer loader by power actuators which are commonly hydraulic cylinders. In addition, the tool is coupled to the lift arm by another power actuator which is also commonly a hydraulic cylinder. An operator manipulating the skid steer loader raises and lowers the lift arm, and manipulates the tool, by actuating the hydraulic cylinders coupled to the lift arm, and the hydraulic cylinder coupled to the tool. When the operator causes the hydraulic cylinders coupled to the lift arm to increase in length, the lift arm moves generally vertically upward. Conversely, when the operator causes the hydraulic cylinders coupled to the lift arm to decrease in length, the lift arm moves generally vertically downward. Similarly, the operator can manipulate the tool (e.g., tilt the bucket) by controlling the hydraulic cylinder coupled to the lift arm and the working tool to increase or decrease in length, as desired.
Skid steer loaders also commonly have an engine which drives a hydraulic pump to, in turn, power hydraulic traction motors which power movement of the skid steer loader. The traction motors are commonly coupled to the wheels through a drive mechanism such as a chain drive.
Typically, the hydraulic circuits that serve the lift arm, the tool and the traction mechanism are controlled by mechanical linkages to levers, pedals, and/or handgrips, all of which can be manipulated by an operator. More recently, the hydraulic circuits controlling the lift and tilt functions (e.g., the lift arm and tool) are controlled by an electronic controller as a function of inputs from an operator interface. The controller serves to control the flow of hydraulic fluid in the hydraulic circuits as a function of the operator inputs. The controller is typically a microprocessor capable of being programmed to correlate the operator input (which is an electrical signal generated by an input mechanism such as from a switch, trigger, handgrip, or button) to the controller output. The controller output is an electrical signal provided, for example, to an electrically controlled solenoid or valve spool, to control hydraulic fluid flow through a valve associated with the solenoid or valve spool. Thus, the hydraulic circuits which control the lift arm and the tool (and possibly auxiliary or other couplers) operate as a function of the output of the controller. Accordingly, control of the various hydraulic implements on the power machine is a function of the operator input as defined by the software associated with the controller. The software loaded on the controller typically includes a set of operating parameters that are predetermined at the factory and loaded onto the controller.
If, after the power machine has left the factory and is used in the field, it is necessary or desirable to alter the performance of the power machine by, for example, adding an implement or attachment to the machine or change operational characteristics of the machine, it may be necessary to modify the software on the controller to change or improve performance of the reconfigured power machine. In addition, after a power machine has been in use for a period of time, it may be necessary or desirable to modify the software on the controller in order to recalibrate certain parameters or upgrade the software to a more current version. In particular, it may be desirable to upgrade the software to improve performance of the power machine and/or make it suitable for use with newly available attachments. To accommodate this reprogramming, it has been necessary with prior art power machines to completely replace components (such as the controller or memory associated therewith, or both). This can be costly and inefficient.
Similarly, testing or monitoring operation of a power machine, or diagnosing a problem on a power machine, can be difficult. For instance, when the power machine is of the type in which the hydraulic circuit is controlled by an electronic controller, performing diagnostics on such a system can be fairly complicated and time consuming.
The present invention provides a service tool for use with a power machine such as a skid steer loader. The service tool allows a field technician to do one or more of the following: monitor operation of the power machine, control the operation of the power machine, perform diagnostics on the power machine and/or modify the operating parameters of the power machine without replacing components. The ability to perform diagnostics in the field results in substantial cost and time savings. The ability to control and monitor the power machine during diagnostics allows the technician to test the machine""s performance and modify the operating parameters of the machine, if necessary.
In an illustrative embodiment of the present invention, the service tool is designed for use with a power machine which includes a hydraulic drive circuit connected to a hydraulic drive motor, a hydraulic actuator circuit connected to a hydraulic actuator, and a controller connected to the hydraulic drive circuit and the hydraulic actuator circuit. The controller has an input, an output and a set of operating parameters which correlate the input to the output. At least one of the hydraulic functions of the power machine operate as a function of the output of the controller. An operator interface unit provides operator actuable inputs, is connected to the controller, and has an output which is a function of an operator interface input. The output of the operator interface unit provides the input to the controller such that the operator interface input controls the operation of the designated hydraulic function.
The service tool illustratively includes a remote start and control device and a computer. The remote start and control device controls the operation of an engine on the power machine and at least one hydraulic function. The diagnostic and control unit includes an interface for interfacing with the controller.
The remote start and control device illustratively includes an unlock input for unlocking the operator controls, a starter input for starting and stopping the power machine, and hydraulic control inputs for controlling or unlocking one or more of the hydraulic functions. The computer illustratively also includes a diagnostic mechanism for scanning the controller, for detecting the operating parameters of the controller, for collecting performance data of the power machine and/or for modifying the operating parameters of the controller.
Another illustrative embodiment of the present invention is a method of controlling, diagnosing and modifying the operation of a power machine using a diagnostic and control unit that includes a remote start and control device connected to a computer. The method illustratively includes the steps of connecting the diagnostic and control unit to the controller on the power machine, unlocking and operating a hydraulic function on the power machine, performing diagnostics on the power machine using the computer and modifying the operating parameters of the controller based on the diagnostics.
The diagnostic method illustratively includes the steps of scanning the controller for (or receiving an input indicative of) a current installed software version, comparing the current software version with an upgrade version, and automatically upgrading the installed software if the current version is different from the upgrade version. The software illustratively includes operating parameters. The diagnostic method may also include the steps of collecting operating performance data as at least one of the hydraulic functions are operated, comparing the data to desired performance specifications and modifying the operating parameters of the controller if the collected data is different from the desired or specified data.